A micro-nano fiber hollow tube and its preparation process

Abstract

The present invention relates to the technical field of micro-nano fiber hollow tubes, and particularly to a micro-nano fiber hollow tube and its preparation process, wherein a core layer micro-nano fiber membrane made of a spinning precursor prepared from polymer A and a skin layer micro-nano fiber membrane made of a spinning precursor prepared from polymer B are rolled and collected by a rolling device to form a double-layer micro-nano fiber cylinder with a skin-core structure, and then the core layer micro-nano fiber is completely dissolved by a selective dissolution process to prepare the hollow tube; wherein, by adjusting the rolling and collecting amount of the skin layer micro-nano fiber membrane and the core layer micro-nano fiber membrane by the rolling device at any time, the diameter of the micro-nano fiber cylinder can be adjusted at any time, thereby adjusting the wall thickness and inner diameter of the micro-nano fiber hollow tube. By combining the spinning process, the rolling process and the selective dissolution process, a micro-nano fiber hollow tube with adjustable fiber orientation and diameter, adjustable hollow tube wall, inner diameter and length, and flexible and simple technology is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-nano fiber hollow tubes, and in particular to a micro-nano fiber hollow tube and a preparation process thereof. Background Art

[0002] In recent years, with the development of nanomaterials and technologies, novel nanomaterials with unique structures and functions have attracted widespread attention. Among them, core-shell nanomaterials with double-layer or multi-layer structures can meet a variety of application requirements. The composite structure of dissimilar core and shell components balances the common characteristics of each component, resulting in core-shell particles with properties that differ from those of the core and shell alone and possess many unique properties, expanding their application range. By removing the core through certain means, hollow micro-nanostructures with controllable pore volume and shell thickness can be obtained.

[0003] Due to the high specific surface area and low density of these structures, they are widely used in the chemical, pharmaceutical, and other fields. The preparation of hollow fibers with high specific surface area has received increasing attention, and much research has been devoted to the preparation of such nanomaterials. Methods for preparing hollow nanofibers primarily include thermally induced phase separation, solvent-induced phase separation, and electrospinning. The thermally induced phase separation method involves mixing a polymer with a high-boiling-point nonsolvent at high temperature to form a homogeneous solution. The solution is then cooled during extrusion, causing the polymer and diluent to separate due to the temperature drop, forming a hollow fiber membrane. The residual diluent in the membrane is then cleaned with an organic solvent such as ethanol, as described in [ZL98807444.3]. A drawback of the thermally induced phase separation method is that it requires high control of the spinning process, requiring precise control of the phase separation between the diluent and polymer. X. Xia et al. dissolved tin chloride and PVP in a mixed solution of ethanol and DMF and prepared nanofibers via electrospinning. Due to the different volatilization rates of the two solvents, the tin chloride and PVP phase separated. After a subsequent high-temperature calcination process, SnO2 hollow fibers were obtained. This method requires the use of two solvents with different volatilization rates. Coaxial electrospinning is a common solution spinning method. [201310024342.2] This involves injecting the spinning solution into the outer tube of a coaxial spinneret and allowing air to enter the inner tube for coaxial electrospinning. This method is simple to operate, but requires a specially designed spinneret with an inner and outer tubular structure. The two-phase system requires stricter control of electrospinning parameters.

[0004] Hollow tubes or cylindrical structures are widely used in the production of medical device materials. For example, artificial blood vessels, nerve catheters, artificial tracheas, etc. all require hollow tube structures. Patent CN114228132A directly uses low-temperature coaxial 3D printing technology to prepare a polycaprolactone hollow tube stent, which can achieve drug loading in the inner layer and has a vascular bionic structure, but the processing requires a long time in a low-temperature environment and the process is complicated; Patent CN114474799A discloses a method for preparing medical hollow tubes, that is, after the coating layer is solidified on the surface of the core wire, the core wire is removed by high-temperature sintering to obtain a coated hollow tube. The above methods can all obtain hollow tubular structures, but they must be processed at low or high temperatures, which has great limitations on material selection. The complex process makes it difficult to adjust the parameters of the hollow tube, and it lacks surface and structural characteristics. When used as a medical device material, it is inferior to nanofiber structure materials. Numerous studies have demonstrated that nanofibers can mimic the structure of the extracellular matrix, possessing high surface area and porosity, facilitating cell adhesion, penetration, and proliferation. Furthermore, highly oriented fibers can induce directional cell growth, improving tissue repair efficiency. Therefore, imparting a hollow tube with an appropriate diameter and a nanofiber structure with adjustable orientation, enabling flexible control of process parameters, and achieving a low technical barrier to entry remain unresolved technical challenges. Summary of the Invention

[0005] In response to the shortcomings of the above-mentioned existing technologies, a micro-nano fiber hollow tube and its preparation process are provided. By combining a spinning process, a winding process and a selective dissolution process, a micro-nano fiber hollow tube with adjustable fiber orientation and diameter, adjustable hollow tube wall, inner diameter and length is obtained, and the technology is flexible and simple.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is a micro-nano fiber hollow tube, which is prepared by rolling and collecting a core layer micro-nano fiber membrane made of a spinning precursor prepared from polymer A and a skin layer micro-nano fiber membrane made from a spinning precursor prepared from polymer B into a double-layer micro-nano fiber cylinder with a skin-core structure through a rolling and rubbing device, and then completely dissolving the core layer micro-nano fiber through a selective dissolution process; wherein, by adjusting the rolling and collecting amount of the skin layer micro-nano fiber membrane and the core layer micro-nano fiber membrane by the rolling and rubbing device at any time, the diameter of the micro-nano fiber cylinder can be adjusted at any time, thereby adjusting the tube wall thickness and inner diameter of the micro-nano fiber hollow tube.

[0007] In the above-mentioned micro-nano fiber hollow tube, the polymer A includes polyvinyl alcohol, polyethylene glycol, polyacrylamide, polypropylene pyrrolidone and other commonly used spinning polymers.

[0008] In the above-mentioned micro-nano fiber hollow tube, the B polymer includes polyglycolide-lactide, polylactide-glycolide, polylactic acid, polyglycolic acid solution, polycaprolactone, polydioxanone, polyhydroxyalkanoate, polybutylene succinate and other commonly used spinning polymers.

[0009] The above-mentioned micro-nano fiber hollow tube, the rolling device includes a winding drum and a driving motor for driving the winding drum; the thickness of the core layer micro-nano fiber membrane or the skin layer micro-nano fiber membrane is 1μm to 10 cm, and the width is 1μm to 100 cm.

[0010] The preparation process of the above-mentioned micro-nano fiber hollow tube includes the following steps:

[0011] (1) Prepare a spinning precursor made of polymer A to prepare a micro-nano fiber membrane, and then use a rolling process to obtain a core layer micro-nano fiber cylinder;

[0012] (2) preparing a spinning precursor prepared from polymer B to prepare a micro-nano fiber membrane, and then using a winding device to obtain a double-layer micro-nano fiber cylinder with a skin-core structure based on the core micro-nano fiber cylinder obtained in step (1);

[0013] (3) The double-layer micro-nano fiber cylinder obtained in step (2) is subjected to a selective dissolution process to completely dissolve the core layer micro-nano fibers, thereby obtaining a hollow tube with only the skin layer micro-nano fibers retained, namely, a micro-nano fiber hollow tube.

[0014] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (1), the micro-nano fibers obtained by electrospinning are collected on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and then the micro-nano fiber membrane is rolled parallel to the axial direction of the winding device to be gathered into a linear ring and placed on one side of the receiving roller for standby use.

[0015] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (2), the micro-nano fibers obtained by electrospinning are collected again on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and the core layer micro-nano fiber cylinder prepared in step (1) is used as the mold matrix, and then the micro-nano fiber membrane prepared in step (2) is rolled and wrapped around the core layer micro-nano fiber cylinder in parallel along the axial direction of the winding device, thereby obtaining a double-layer micro-nano fiber cylinder with a skin-core structure.

[0016] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (3), the selective dissolution process is: immersing the double-layer micro-nano fiber cylinder in water, anhydrous ethanol or other solvents or solutions that only dissolve the core layer micro-nano fibers, and the immersion time is 1 second to 1 year. Heating can also be used to promote its dissolution.

[0017] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (1), the spinning precursor prepared by the polymer A includes polyvinyl alcohol solution, polyethylene glycol solution, polyacrylamide solution, polypropylene pyrrolidone solution and other commonly used electrospinning polymer material solutions; in the step (2), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer B includes polyglycolide-lactide solution, polylactide-glycolide solution, polylactic acid solution, polyglycolic acid solution, polycaprolactone solution, polydioxanone solution, polyhydroxyalkanoate solution, polybutylene succinate solution and other commonly used electrospinning polymer solutions.

[0018] In the above-mentioned preparation process of micro-nano fiber hollow tubes, the structure of the electrospinning nozzle is a needle-type nozzle or a needle-free nozzle; the needle-type nozzle is a single-needle or multi-needle combination, and is a single-axis, coaxial or multi-channel combination; the needle-free nozzle is one or more combinations of metal wire, slit, ring, cylinder, disc, and sphere; the electrospinning applied voltage is -100 kV to +100 kV, the spinning solution extrusion rate is 0.1 μL / h to 10 mL / h, the distance between the spinning nozzle and the winding device is 0.1 cm to 100 cm, and the winding device rotation speed is 1 rpm to 100,000 rpm.

[0019] The beneficial effect of the micro-nano fiber hollow tube and the preparation process thereof of the present invention is that the micro-nano fiber hollow tube is prepared by combining the micro-nano fiber membrane prepared by the spinning process with the rolling process and the selective dissolution process, thereby achieving flexible control of process parameters and low technical threshold.

[0020] The use of winding drum collection can ensure that the micro-nano fibers are oriented and arranged in the same direction under the action of high-speed rotation; the use of a transverse parallel winding method to prepare micro-nano fiber solid cylinders can adjust the cylinder diameter at any time, thereby adjusting the wall and inner diameter of the hollow tube; the use of a selective dissolution process can ensure that the core layer micro-nano fibers are completely removed without affecting the skin layer micro-nano fibers, ensuring that the hollow tube structure is stable and complete. In summary, the drum collection and transverse parallel winding methods can produce micro-nano fiber cylinders with highly oriented fibers, flexible and variable tube walls, inner diameters and lengths, and distinct inner and outer double-layer structures. The selective dissolution process can efficiently remove the core layer micro-nano fibers without changing the structural morphology of the skin layer micro-nano fiber hollow tube wall. The micro-nano fiber hollow tube prepared by the present invention has adjustable fiber orientation and diameter, and the hollow tube wall, caliber and length are flexible and variable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the process flow of the micro-nano fiber hollow tube provided in this application.

[0022] Figure 2 These are the longitudinal photos of the micro-nano fiber hollow tubes with different calibers provided in this application.

[0023] Figure 3 These are the horizontal physical photos of micro-nano fiber hollow tubes of different calibers provided in this application.

[0024] Figure 4 This is an electron microscope photograph of the surface morphology of the micro-nano fiber hollow tube provided in this application.

[0025] Figure 5 This is a tensile strength-elongation curve of micro-nano fiber hollow tubes of different calibers provided in this application. Implementation Method

[0026] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] A micro-nano fiber hollow tube is prepared by rolling and collecting a core micro-nano fiber membrane made of a spinning precursor prepared from polymer A and a skin micro-nano fiber membrane made from a spinning precursor prepared from polymer B into a double-layer micro-nano fiber cylinder with a skin-core structure through a rolling device, and then completely dissolving the core micro-nano fiber through a selective dissolution process; wherein, by adjusting the rolling and collecting amount of the skin micro-nano fiber membrane and the core micro-nano fiber membrane by the rolling device at any time, the diameter of the micro-nano fiber cylinder can be adjusted at any time, thereby adjusting the tube wall thickness and inner diameter of the micro-nano fiber hollow tube.

[0028] In the above-mentioned micro-nano fiber hollow tube, the polymer A includes polyvinyl alcohol, polyethylene glycol, polyacrylamide, polypropylene pyrrolidone and other commonly used spinning polymers.

[0029] In the above-mentioned micro-nano fiber hollow tube, the B polymer includes polyglycolide-lactide, polylactide-glycolide, polylactic acid, polyglycolic acid solution, polycaprolactone, polydioxanone, polyhydroxyalkanoate, polybutylene succinate and other commonly used spinning polymers.

[0030] The above-mentioned micro-nano fiber hollow tube, the rolling device includes a winding drum and a driving motor for driving the winding drum; the thickness of the core layer micro-nano fiber membrane or the skin layer micro-nano fiber membrane is 1μm to 10cm, and the width is 1μm to 100cm. Example

[0031] The preparation process of the above-mentioned micro-nano fiber hollow tube includes the following steps:

[0032] (1) Prepare a spinning precursor made of polymer A to prepare a micro-nano fiber membrane, and then use a rolling process to obtain a core layer micro-nano fiber cylinder;

[0033] (2) preparing a spinning precursor prepared from polymer B to prepare a micro-nano fiber membrane, and then using a winding device to obtain a double-layer micro-nano fiber cylinder with a skin-core structure based on the core micro-nano fiber cylinder obtained in step (1);

[0034] (3) The double-layer micro-nano fiber cylinder obtained in step (2) is subjected to a selective dissolution process to completely dissolve the core layer micro-nano fibers, thereby obtaining a hollow tube with only the skin layer micro-nano fibers retained, namely, a micro-nano fiber hollow tube.

[0035] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (1), the micro-nano fibers obtained by electrospinning are collected on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and then the micro-nano fiber membrane is rolled parallel to the axial direction of the winding device to be gathered into a linear ring and placed on one side of the receiving roller for standby use.

[0036] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (2), the micro-nano fibers obtained by electrospinning are collected again on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and the core layer micro-nano fiber cylinder prepared in step (1) is used as the mold matrix, and then the micro-nano fiber membrane prepared in step (2) is rolled and wrapped around the core layer micro-nano fiber cylinder in parallel along the axial direction of the winding device, thereby obtaining a double-layer micro-nano fiber cylinder with a skin-core structure.

[0037] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (3), the selective dissolution process is: immersing the double-layer micro-nano fiber cylinder in water, anhydrous ethanol or other solvents or solutions that only dissolve the core layer micro-nano fibers, and the immersion time is 1 second to 1 year. Heating can also be used to promote its dissolution.

[0038] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (1), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer A includes polyvinyl alcohol solution, polyethylene glycol solution, polyacrylamide solution, polypropylene pyrrolidone solution and other commonly used electrospinning polymer material solutions; in the step (2), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer B includes polyglycolide-lactide solution, polylactide-glycolide solution, polylactic acid solution, polyglycolic acid solution, polycaprolactone solution, polydioxanone solution, polyhydroxyalkanoate solution, polybutylene succinate solution and other commonly used electrospinning polymer solutions.

[0039] In the above-mentioned preparation process of micro-nano fiber hollow tubes, the structure of the electrospinning nozzle is a needle-type nozzle or a needle-free nozzle; the needle-type nozzle is a single-needle or multi-needle combination, and is a single-axis, coaxial or multi-channel combination; the needle-free nozzle is one or more combinations of metal wire, slit, ring, cylinder, disc, and sphere; the electrospinning applied voltage is -100 kV, the spinning solution extrusion rate is 0.1 μL / h, the distance between the spinning nozzle and the winding device is 0.1 cm, and the winding device rotation speed is 1 rpm. Example

[0040] The preparation process of the above-mentioned micro-nano fiber hollow tube includes the following steps:

[0041] (1) Prepare a spinning precursor made of polymer A to prepare a micro-nano fiber membrane, and then use a rolling process to obtain a core layer micro-nano fiber cylinder;

[0042] (2) preparing a spinning precursor prepared from polymer B to prepare a micro-nano fiber membrane, and then using a winding device to obtain a double-layer micro-nano fiber cylinder with a skin-core structure based on the core micro-nano fiber cylinder obtained in step (1);

[0043] (3) The double-layer micro-nano fiber cylinder obtained in step (2) is subjected to a selective dissolution process to completely dissolve the core layer micro-nano fibers, thereby obtaining a hollow tube with only the skin layer micro-nano fibers retained, namely, a micro-nano fiber hollow tube.

[0044] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (1), the micro-nano fibers obtained by electrospinning are collected on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and then the micro-nano fiber membrane is rolled parallel to the axial direction of the winding device to be gathered into a linear ring and placed on one side of the receiving roller for standby use.

[0045] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (2), the micro-nano fibers obtained by electrospinning are collected again on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and the core layer micro-nano fiber cylinder prepared in step (1) is used as the mold matrix, and then the micro-nano fiber membrane prepared in step (2) is rolled and wrapped around the core layer micro-nano fiber cylinder in parallel along the axial direction of the winding device, thereby obtaining a double-layer micro-nano fiber cylinder with a skin-core structure.

[0046] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (3), the selective dissolution process is: immersing the double-layer micro-nano fiber cylinder in water, anhydrous ethanol or other solvents or solutions that only dissolve the core layer micro-nano fibers, and the immersion time is 1 second to 1 year. Heating can also be used to promote its dissolution.

[0047] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (1), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer A includes polyvinyl alcohol solution, polyethylene glycol solution, polyacrylamide solution, polypropylene pyrrolidone solution and other commonly used electrospinning polymer material solutions; in the step (2), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer B includes polyglycolide-lactide solution, polylactide-glycolide solution, polylactic acid solution, polyglycolic acid solution, polycaprolactone solution, polydioxanone solution, polyhydroxyalkanoate solution, polybutylene succinate solution and other commonly used electrospinning polymer solutions.

[0048] In the above-mentioned preparation process of micro-nano fiber hollow tubes, the structure of the electrospinning nozzle is a needle-type nozzle or a needle-free nozzle; the needle-type nozzle is a single-needle or multi-needle combination, and is a single-axis, coaxial or multi-channel combination; the needle-free nozzle is one or more combinations of metal wire, slit, ring, cylinder, disc, and sphere; the electrospinning external voltage is 50 kV, the spinning solution extrusion rate is 7 mL / h, the distance between the spinning nozzle and the winding device is 50 cm, and the winding device rotation speed is 8000 rpm. Example

[0049] The preparation process of the above-mentioned micro-nano fiber hollow tube includes the following steps:

[0050] (1) Prepare a spinning precursor made of polymer A to prepare a micro-nano fiber membrane, and then use a rolling process to obtain a core layer micro-nano fiber cylinder;

[0051] (2) preparing a spinning precursor prepared from polymer B to prepare a micro-nano fiber membrane, and then using a winding device to obtain a double-layer micro-nano fiber cylinder with a skin-core structure based on the core micro-nano fiber cylinder obtained in step (1);

[0052] (3) The double-layer micro-nano fiber cylinder obtained in step (2) is subjected to a selective dissolution process to completely dissolve the core layer micro-nano fibers, thereby obtaining a hollow tube with only the skin layer micro-nano fibers retained, namely, a micro-nano fiber hollow tube.

[0053] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (1), the micro-nano fibers obtained by electrospinning are collected on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and then the micro-nano fiber membrane is rolled parallel to the axial direction of the winding device to be gathered into a linear ring and placed on one side of the receiving roller for standby use.

[0054] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (2), the micro-nano fibers obtained by electrospinning are collected again on a winding device in a form with controllable orientation to form a micro-nano fiber membrane with a certain thickness and width, and the core layer micro-nano fiber cylinder prepared in step (1) is used as the mold matrix, and then the micro-nano fiber membrane prepared in step (2) is rolled and wrapped around the core layer micro-nano fiber cylinder in parallel along the axial direction of the winding device, thereby obtaining a double-layer micro-nano fiber cylinder with a skin-core structure.

[0055] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in step (3), the selective dissolution process is: immersing the double-layer micro-nano fiber cylinder in water, anhydrous ethanol or other solvents or solutions that only dissolve the core layer micro-nano fibers, and the immersion time is 1 second to 1 year. Heating can also be used to promote its dissolution.

[0056] In the above-mentioned preparation process of the micro-nano fiber hollow tube, in the step (1), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer A includes polyvinyl alcohol solution, polyethylene glycol solution, polyacrylamide solution, polypropylene pyrrolidone solution and other commonly used electrospinning polymer material solutions; in the step (2), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer B includes polyglycolide-lactide solution, polylactide-glycolide solution, polylactic acid solution, polyglycolic acid solution, polycaprolactone solution, polydioxanone solution, polyhydroxyalkanoate solution, polybutylene succinate solution and other commonly used electrospinning polymer solutions.

[0057] In the above-mentioned preparation process of micro-nano fiber hollow tubes, the structure of the electrospinning nozzle is a needle-type nozzle or a needle-free nozzle; the needle-type nozzle is a single-needle or multi-needle combination, and is a single-axis, coaxial or multi-channel combination; the needle-free nozzle is one or more combinations of metal wire, slit, ring, cylinder, disc, and sphere; the electrospinning external voltage is 100 kV, the spinning solution extrusion rate is 10 mL / h, the distance between the spinning nozzle and the winding device is 100 cm, and the winding device rotation speed is 100,000 rpm. Example

[0058] The similarities between this embodiment and embodiment 1 are not repeated here, and the differences are as follows:

[0059] The following uses the outer spinning solution prepared by polylactide-caprolactone (PLCL) and hexafluoroisopropanol and the inner spinning solution prepared by polyvinyl alcohol (PVA) and deionized water as an example to carry out spinning. Figure 1 As shown, the process includes the following steps: (1) dissolving PLCL in hexafluoroisopropanol, stirring, dissolving, and standing to prepare an outer layer spinning solution with a concentration of 13%, mixing PVA into deionized water, heating at 90°C, stirring, dissolving, and standing to prepare an inner layer spinning solution with a concentration of 15%; (2) loading the PVA spinning solution into a syringe, the syringe propulsion rate is 0.4 mL / h, the external voltage is set to +18 kV, and the winding drum speed is set to 2000 rpm; (3) collecting the PVA nanofibers into a PVA nanofiber membrane with a certain thickness; (4) rolling the nanofiber membrane parallel to the axial direction of the receiving roller to form a circular solid cylinder, and standing it on one side of the roller for use; (5) The PLCL spinning solution was loaded into the syringe, the syringe propulsion rate was 0.8 mL / h, the external voltage was set to +18 kV, and the winding drum speed was set to 2000 rpm; (6) The PLCL nanofibers were collected to form a PLCL nanofiber membrane with a certain thickness; (7) The PVA nanofiber solid cylinder was used as the mold matrix, and the PLCL nanofiber membrane was rolled and wrapped around the PVA nanofiber solid cylinder along the axial direction of the receiving roller to form a double-layer nanofiber solid cylinder; (8) The double-layer nanofiber solid cylinder was cut and removed, freeze-dried for a period of time, and then completely immersed in 60°C hot water for 2 h to obtain a PLCL nanofiber hollow tube. Figure 2 and Figure 3 The longitudinal and transverse photos of the nanofiber hollow tube are shown respectively. Figure 4 The transverse SEM images of the nanofiber hollow tube are displayed, and the diameters and orientations of 100 nanofibers are randomly calculated, and the nanofiber diameter is found to be 384.6±86.2nm and the orientation is 90±5°. Figure 5The tensile strength-elongation curves of two calibers of nanofiber hollow tubes are displayed, and 5 groups of parallel samples are taken to test their mechanical properties. The results show that the average breaking strength of the larger caliber nanofiber hollow tube 1 is 5.2±0.29N, the breaking strength is 36.8±9.4MPa, and the Young's modulus is 431.3±59.3MPa. The average breaking strength of the smaller caliber nanofiber hollow tube 2 is 4.7±0.3N, the breaking strength is 35.2±7.3MPa, and the Young's modulus is 360.3±62.3MPa. Example

[0060] The similarities between this embodiment and embodiment 1 are not repeated here. The difference lies in that in the above-mentioned process for preparing the micro-nano fiber hollow tube, a polymer melt can also be used for spinning in step (1) or step (2).

[0061] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A micro-nano fiber hollow tube, characterized by: The invention relates to a core layer micro-nano fiber membrane made of micro-nano fibers obtained by electrospinning a spinning precursor prepared from polymer A in a form with controllable orientation, and a skin layer micro-nano fiber membrane made of micro-nano fibers obtained by electrospinning a spinning precursor prepared from polymer B in a form with controllable orientation, which are prepared into a double-layer annular micro-nano fiber solid cylinder with a skin-core structure by a rolling device, and then the core layer micro-nano fibers are completely dissolved by a selective dissolution process; wherein, by adjusting the rolling and collecting amount of the skin layer micro-nano fiber membrane and the core layer micro-nano fiber membrane by the rolling device at any time, the diameter of the micro-nano fiber cylinder can be adjusted at any time, thereby adjusting the tube wall thickness and inner diameter of the micro-nano fiber hollow tube; the rolling device includes a winding drum, and the winding drum is used for collection. The micro-nano fibers are oriented and arranged in the same direction under the action of high-speed rotation, and the inner layer annular micro-nano fiber solid cylinder and the double layer annular micro-nano fiber solid cylinder are respectively prepared by a transverse parallel rolling method.

2. The micro-nano fiber hollow tube according to claim 1, characterized in that: The A polymer includes polyvinyl alcohol, polyethylene glycol, polyacrylamide, polypropylene pyrrolidone and other commonly used spinning polymers.

3. The micro-nano fiber hollow tube according to claim 2, characterized in that: The B polymer includes polyglycolide-lactide, polylactide-glycolide, polylactic acid, polyglycolic acid solution, polycaprolactone, polydioxanone, polyhydroxyalkanoate, polybutylene succinate and other commonly used spinning polymers.

4. The micro-nano fiber hollow tube according to claim 3, characterized in that: The winding device includes a winding drum and a driving motor for driving the winding drum; the thickness of the core layer micro-nano fiber membrane or the skin layer micro-nano fiber membrane is 1 μm to 10 cm, and the width is 1 μm to 100 cm.

5. A process for preparing the micro-nano fiber hollow tube according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) preparing a spinning precursor made of polymer A to prepare a micro-nano fiber membrane, and then using a rolling process to obtain an inner ring-shaped micro-nano fiber solid cylinder as the core layer; (2) preparing a spinning precursor prepared from polymer B to prepare a micro-nano fiber membrane, and then using a rolling device to obtain a double-layer annular micro-nano fiber solid cylinder with a skin-core structure based on the inner layer annular micro-nano fiber solid cylinder obtained in step (1); (3) The double-layer micro-nano fiber cylinder obtained in step (2) is subjected to a selective dissolution process to completely dissolve the core layer micro-nano fibers to obtain a hollow tube with only the skin layer micro-nano fibers retained, namely, a micro-nano fiber hollow tube; In the step (1), the micro-nano fibers obtained by electrospinning are collected on a winding device in a form with a controllable degree of orientation to form a micro-nano fiber membrane with a certain thickness and width, and then the micro-nano fiber membrane is rolled parallel to the axial direction of the winding device to form an inner layer of annular micro-nano fiber solid cylinders and placed on one side of a receiving drum for standby use; In the step (2), the micro-nano fibers obtained by electrospinning are collected again on a winding device in a form with a controllable degree of orientation to form a micro-nano fiber membrane with a certain thickness and width. The core layer micro-nano fiber cylinder prepared in step (1) is used as a mold matrix, and then the micro-nano fiber membrane prepared in step (2) is rolled and wrapped around the core layer micro-nano fiber cylinder in parallel along the axial direction of the winding device, thereby obtaining a double-layer annular micro-nano fiber solid cylinder with a skin-core structure; In step (1) and step (2), the winding device includes a winding drum, which is used for collection. The micro-nano fibers are oriented and arranged in the same direction under the action of high-speed rotation, and a transverse parallel winding method is used to prepare an inner-layer annular micro-nano fiber solid cylinder and a double-layer annular micro-nano fiber solid cylinder.

6. The process for preparing the micro-nano fiber hollow tube according to claim 5, characterized in that: In step (3), the selective dissolution process is: immersing the double-layer micro-nano fiber cylinder in water, anhydrous ethanol or other solvents or solutions that only dissolve the core layer micro-nano fibers, and the immersion time is 1 second to 1 year, or heating is used to promote its dissolution.

7. The process for preparing the micro-nano fiber hollow tube according to claim 6, characterized in that: In the step (1), the micro-nano fiber membrane is prepared by an electrospinning process, and the spinning precursor prepared by the polymer A includes polyvinyl alcohol solution, polyethylene glycol solution, polyacrylamide solution, polypropylene pyrrolidone solution and other commonly used electrospinning polymer material solutions; in the step (2), the micro-nano fiber membrane is prepared by an electrospinning process; the spinning precursor prepared by the polymer B includes polyglycolide-lactide solution, polylactide-glycolide solution, polylactic acid solution, polyglycolic acid solution, polycaprolactone solution, polydioxanone solution, polyhydroxyalkanoate solution, polybutylene succinate solution and other commonly used electrospinning polymer solutions.

8. The process for preparing the micro-nano fiber hollow tube according to claim 7, characterized in that: The structure of the electrospinning nozzle is a needle-type nozzle or a needle-free nozzle; the needle-type nozzle is a single-needle or multi-needle combination, and is a single-axis, coaxial or multi-channel combination; the needle-free nozzle is one or more combinations of metal wire, slit, ring, cylinder, disc, and sphere; the electrospinning applied voltage is -100 kV to +100 kV, the spinning solution extrusion rate is 0.1 μL / h to 10 mL / h, the distance between the spinning nozzle and the winding device is 0.1 cm to 100 cm, and the winding device rotation speed is 1 rpm to 100,000 rpm.

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